Sickle cell anaemia (SCA)

How does SCA affect the USA?

Prevalent in 1:500 African Americans.

What is SCA caused by?

The production of abnormal oxygen.

What occurs to the deoxygenated RDC?

Able to carry oxygen to a target cell but when deoxygenated the RBC becomes sickle.

What occurs to the plasma membrane in SCA?

Is contorted and fragile and can burst as it is under stress.

What occurs to the flow of oxygen?

The clumps are less able to deliver oxygen, leading to low oxygen levels in blood. 

What does SCA cause for blood vessels?

• Sickle red blood cells become lodged in blood vessels leading to poor downstream of oxygen delivery, is Chemin (restricted blood supply) and infraction (blocked artery).

• Vessel blockages - Causes episodes of pain, sores, ulcers, can result in organ damage (interruption of blood to spleen, liver), a stroke.

What type of disease is SCA?

Is a monogenic autosomal recessive disorder.

What is sickle cell trait (SCT)

Heterozygote carriers actually have some sickle cells (sickle cell trait), but little disease, which is very benign.

What can SCA and SCT produce resistance to?

SCA and SCT produce some resistance to malaria as the plasmodium parasite causes sickle cells to burst before they can replicate (sporozoites).

What are the treatments fro SCA?

• There is no cure. 

• Painkillers - Or intravenous fluid introduction, to alleviate pain of crisis (sickle cells block oxygen flow to tissues/joints). Saline can expand blood vessels to allow blockages through.

• Blood transfusion - To increase the number of normal blood cells in circulation, many visits and must have a matching donor. 

• Hydroxyurea/hydroxycarbamide (anti cancer drug) - Reduces the incidence of crimes and acute lung syndrome (SC blocking the lung), by stimulating foetal haemoglobin production. 

• Antibiotics - Sufferers prone to infection, due to spleen damages by SCc. 

• Health maintenance - Good diet, hygiene, infection monitoring. 

• Combined treatments have led to an increase in life expectancy. 

• Crizanlizumab - Is a therapeutic based on a monoclonal antibody. These bind to proteins preventing interaction between blood cells and endothelial cells reducing vaso-occlusion.